A virtual network is a computing network having virtual network links. Virtual network links do not require a physical connection, although a given virtual network link can include a physical connection, either wired or wireless. Virtual networks are generally achieved through network virtualization protocols layered on top of a physical network. Examples of virtual networks include virtual local area networks (VLANs), virtual private networks (VPNs), and virtual private LAN service (VPLS). Virtual networks can include one or more physical nodes, each hosting one or more virtual nodes. For example, in a hypervisor, network traffic between multiple virtual machines (VMs) is routed through a virtual switch or a virtual router. Similar to physical networks, virtual networks generally include one or more virtual switches, and may also include physical switches and routers.
A virtual switch is a software component that creates virtual connectivity between virtual ports on VMs. The virtual switch simulates a physical switch, performing packet switching between virtual nodes. A virtual node generally includes one or more virtual network interface cards (NICs) and can be implemented within a VM. The virtual switch generally includes multiple virtual ports through which packets are routed among the various connected virtual nodes. Virtual switch creates virtual connectivity between virtual NICs through virtual ports.